CHICAGO (CBS) — Two planes began their takeoffs on intersecting runways at Chicago’s Midway airport on Tuesday evening, before being ordered to stop by air traffic control and averting a collision in the center of the airport, the FAA confirmed.

The two planes involved were Southwest Flight 3828 bound for Tulsa, Okla., and Delta Flight 1328, headed to Atlanta.

“The Federal Aviation Administration is investigating an incident that occurred shortly before 7:40 p.m. Tuesday at Chicago Midway Airport,” the FAA said in a statement.

Preliminary information indicates that the Southwest Flight was cleared for takeoff on Runway 31-Center, the FAA said.

As that aircraft began its takeoff, an air traffic controller noticed that the Delta flight had also begun rolling on Runway 4-Right without proper clearance.

The controller alerted the Delta crew to stop immediately.

The Southwest crew chose to stop as well.

Each aircraft stopped more than 2,000 feet from the runway intersection in the center of the airport, according to the FAA’s preliminary investigation.

Jetwhine.com publisher and commercial pilot Rob Mark says the runways both planes were on, intersect.

“Just knowing that there were two aircraft of that size headed to the same intersection at the same time…this could have been catastrophic,” Mark said.

Southwest said in a statement that Flight 3828 returned to the terminal to file “necessary reports and tasks. The flight later continued onward to Tulsa without further incident.”

Delta said in a statement that the airline is cooperating with the FAA. Flight 1328 eventually continued to Atlanta without incident.

(Credit: FAA)

(Credit: FAA)

Here is a transcript of the conversations with air traffic control:

ATC: (inaudible)…1328 stop! Stop! Stop!
(BEEPING SOUND)
DELTA PILOT: 1328, Stopping
ATC: 1328 make the right turn on to uh, taxiway Delta, right turn to Delta, hold short runway four-right.
(INAUDIBLE)
ATC: You keep answering for each other, it’s Southwest 3828 and Delta 1328…

SW PILOT 11:12: Southwest 3828
ATC: Go ahead sir.
SW PILOT: …were we the ones clear for take-off?
ATC: Yessir, you were, you were the one – you were doing what you were supposed to be doing.
SW PILOT: …Delta was rolling also?
ATC: Yes…he took your call sign, somebody kept stepping on ya, trying to figure out who it was and then, that’s why I reiterated that it was you that I was clearing for take-off.